Morse Taper or 12.7mm Shank for 29mm drill bit?

[Optimark]

I have ordered a Beall tap specific for my Tecknatool lathe spindle, which is 1¼" x 8 TPI.

425580

I don't have the right size drill for doing the pre-tapped hole, so I am on the market for one. The size I wish to purchase is 29mm and they are quite cheap from Chinese sources. As the bit will get nominal use and be used exclusively in timber, I am not concerned about the steel or longevity factor.

What does interest me is whether I should pick one with a reduced shank, or one with a MT2 shank, which would go directly into my tail stock?

Thoughts?

Mick.

[Lappa]

I believe MT2 shank drills finish at 23mm. After that it’s MT3. Probably need to get a reduced shank.

[Old Croc]

Or buy a single forstner bit.
Rgds,
Crocy

[joe greiner]

Or buy a single forstner bit.
Rgds,
Crocy
If you don't have, or can't find, a 29mm Forstner bit, use 1 1/8 Imperial - recommended hole size for 1 1/4 - 8.

Cheers,
Joe

[Optimark]

I believe MT2 shank drills finish at 23mm. After that it’s MT3. Probably need to get a reduced shank.


You are correct, I didn't know they went up a size from then on.

Mick.

[Optimark]

If you don't have, or can't find, a 29mm Forstner bit, use 1 1/8 Imperial - recommended hole size for 1 1/4 - 8.

Cheers,
Joe

That is an option, but at this stage I'm trying to get a 29mm bit. Apart from drill bits for rivets, I don't have any non metric drill bits; not in a screaming hurry to start adding non metric stuff at this stage of my life.

I grew up with feet and inches, a much younger brother grew up with metric. I use metric, he uses inches; crazy world eh?

Mick.

[Optimark]

Yes I know, the tapping die I have just bought is in inches. :D

Mick.

[RobbieB]

I have a box of old bowling ball bits in the shed, all MT2 and up to 1 1/4. I'll have a look tomorrow and see if there is a spare 1 1/8. If there is one it will be carbide tipped and probably blunt.
Cheers, Robbie.

[Optimark]

I have a box of old bowling ball bits in the shed, all MT2 and up to 1 1/4. I'll have a look tomorrow and see if there is a spare 1 1/8. If there is one it will be carbide tipped and probably blunt.
Cheers, Robbie.

Hmm, bowling ball bits, never would have thought of them. Does that mean we all have imperial digits? :o

Perhaps they are use imperial sized holes for 10 pin bowling balls as the originator of 10 pin bowling is the European 9 pin bowling; they don't have holes in their balls.

Kegelbahn is probably the most popular in Germany, I've played it in quite a few places in Germany; far more interesting than 10 pin bowling. It is played outside, inside, in special bowling lanes mostly underground in pubs and clubs, or even in backyards. Skittles is probably a more correct translation and applies equally to 10 pin bowling.

I will consider your offer, but as previously mentioned, I am quite averse to non metric stuff.

Mick.

[ian]

That is an option, but at this stage I'm trying to get a 29mm bit. Apart from drill bits for rivets, I don't have any non metric drill bits; not in a screaming hurry to start adding non metric stuff at this stage of my life.
Does a 29 mm bit even exist other than as a special order?

do you want a forstner, saw tooth forstner, brad point, speed bore, auger (machine or hand), or ???

if a speed bore would work for you, you could always get a 30 mm bit and grind 0.5 mm off each side.

[Lappa]

29mm bits are readily available but mostly with MT3 shanks.

https://www.machineryhouse.com.au/D333

[BobL]

You can still use a 29 mm MT3 bit but you will need to get an MT3 female / MT2 male adapter/extension to use it in an MT2 socket.

The drill will cost about $60 for a cheap one here in Aus.
Mcjing has the extension sleeve for $42

If you want a quality chinese bit then CTC tools in HK have 29mm drill bits for $27 but they want $20 for shipping
An Ebay seller in Victoria has them for around $40.

[ian]

that's starting to look an expensive way to side step purchasing an 1-1/8" bit


BTW, are the suggested MT twist bits really suitable for drilling wood?

[BobL]

that's starting to look an expensive way to side step purchasing an 1-1/8" bit
BTW, are the suggested MT twist bits really suitable for drilling wood?

They cut wood just fine, but if you want a clean edged hole you might need to use a sacrificial piece of wood on top.

[Optimark]

Well a plethora of information, many thanks to all who have replied.

In general I am now leaning towards a 29mm reduced shank bit. One of the things all of now can experience, is world wide shopping; it is simply unbelievable what is now on offer.

For Ian, in the past I have used a system for drilling timber with conventional HSS metal drill bits using some sacrificial timber to keep things clean; I will keep doing this as it does work. Previously drilled and tapped timber to M30 x 3.5 very successfully.

Unfortunately my lathe uses a different size to what the majority of lathes in Australia now have. I wonder why Australia has adopted that smaller size (M30 x 3.5) when pretty much the rest of the world uses M33 x 3.5 or 1¼" x 8.

I'll let you know what I eventually get.

Mick.

[NCArcher]

425877What about one of these if it is only for occasional use.

[Optimark]

425877What about one of these if it is only for occasional use.


We have two of these at my Men's Shed, I gave them serious thought but decided their accuracy was a bit suspect, although accuracy in this field is not that important. The deciding factor was the centre screw makes doing small depth holes impossible.

Good idea though, thanks.

Mick.

[Old Croc]

McJing's have a 1 1/4 inch sawtooth bit for $12. Thats what I would use.
Crocy.

[ian]

Does McJing's have a 1-1/8" saw tooth bit?
Mick wants to cut a 1-1/4" thread so needs to first drill a smaller pilot hole.

[Old Croc]

If you don't have, or can't find, a 29mm Forstner bit, use 1 1/8 Imperial - recommended hole size for 1 1/4 - 8.

Cheers,
Joe
Ian, this is where I got the quoted size from.
Crocy.

[ian]

interesting how we both have drawn different interpretations from Joe's post.

[Old Croc]

interesting how we both have drawn different interpretations from Joe's post.
Sorry Ian, and everyone else, I hit the wrong number, I meant 1 1/8th bit. I have the same spindle thread on my Laguna and I cut my own threads for accessories on my metal lathe, so I know the pilot hole is actually 1.128 inches, so a 1 1/8 bit is close enough for timber. This UN thread is mainly used in the American market. I had a look at one of those Beale taps when I was in the US recently, but decided I did not need another toy.
Rgds,
Crocy.

[joe greiner]

For almost all thread systems, the "official" pilot hole sizes provide about 75% of full engagement. Smaller engagement of 55-60% is often satisfactory for strength. Larger engagement can lead to broken taps, and is not encouraged. In timber especially, "close enough" really is close enough.

Cheers,
Joe

[hughie]

If you buy a second hand drill bit it will save you a fair bit, try ebay.If the taper is wrong just get it turned off down whatever you want , it wont be hard,this is a fairly common practice and as stated metric or imperial for wood near enough is good enough.

[Paul39]

As I do about 90% bowls a chuck is always on the lathe, and I have a drive center that fits into the center of the chucks for spindles. Oneway chuck system.

If you have a chuck, you might just turn a spigot that fits the most used set of jaws on the chuck, rather than drilling and tapping. I have sanding disks, padded disks to hold the inside of finished bowls for bottom finishing, face plates, big cone drives, small female cone drive to hold tubing, etc., etc., all with a spigot that I grab in the chuck.

Happy and prosperous New Year to all.

[Optimark]

The drill bit I ordered online arrived, total cost delivered to me was $10.16 AUD. This was quite lower than I expected, pleasant surprise to be honest. I wasn't too worried about steel quality as wood is certainly not as hard as steel and I would think anything I'm going to be drilling should be handled quite well with what I ended up with.

Many thanks to all and sundry who replied, all information was gratefully received.

I whipped up a bit of suitably sized timber from a bed post, scrounged from a nature strip find. It's pine but is what I decided to cut my first threads on to get an idea of how well or not so well things would work. To be honest, I am more than impressed with what I received. To put things into perspective, the pilot hole is 12mm.

Mick.

427291427292427293427294427295

[Optimark]

More pictures.


427299 427298 427297 427296